Mixed-method pre-cooling reduces physiological demand without improving performance of medium-fast bowling in the heat     

Minett GM  Duffield R  Kellett A  Portus M 《Journal of sports sciences》2012,30(9):907-915

This study examined physiological and performance effects of pre-cooling on medium-fast bowling in the heat. Ten, medium-fast bowlers completed two randomised trials involving either cooling (mixed-methods) or control (no cooling) interventions before a 6-over bowling spell in 31.9±2.1°C and 63.5±9.3% relative humidity. Measures included bowling performance (ball speed, accuracy and run-up speeds), physical characteristics (global positioning system monitoring and counter-movement jump height), physiological (heart rate, core temperature, skin temperature and sweat loss), biochemical (serum concentrations of damage, stress and inflammation) and perceptual variables (perceived exertion and thermal sensation). Mean ball speed (114.5±7.1 vs. 114.1±7.2 km · h(-1); P = 0.63; d = 0.09), accuracy (43.1±10.6 vs. 44.2±12.5 AU; P = 0.76; d = 0.14) and total run-up speed (19.1±4.1 vs. 19.3±3.8 km · h(-1); P = 0.66; d = 0.06) did not differ between pre-cooling and control respectively; however 20-m sprint speed between overs was 5.9±7.3% greater at Over 4 after pre-cooling (P = 0.03; d = 0.75). Pre-cooling reduced skin temperature after the intervention period (P = 0.006; d = 2.28), core temperature and pre-over heart rates throughout (P = 0.01-0.04; d = 0.96-1.74) and sweat loss by 0.4±0.3 kg (P = 0.01; d = 0.34). Mean rating of perceived exertion and thermal sensation were lower during pre-cooling trials (P = 0.004-0.03; d = 0.77-3.13). Despite no observed improvement in bowling performance, pre-cooling maintained between-over sprint speeds and blunted physiological and perceptual demands to ease the thermoregulatory demands of medium-fast bowling in hot conditions.  相似文献   

La enseñanza de contenidos específicos en matemáticas     

Geoffrey Howson  Brian Wilson 《Cultura y Educación》2013,25(11-12):121-137

¿Matemáticas para todos o matemáticas de élite? ¿Lenguaje matemático o matemática aplicada? En la base de las últimas reformas educativas de todo el mundo no dejan de estar presentes dilemas, reales unas veces, ficticios otras, que tienen mucho que ver con los supuestos políticos—ideológicos—que sustenten los diseñadores de esa reforma respecto al papel de la educación y a los que no se sustrae la enseñanza de las matemáticas…  相似文献   

Children's Developing Mathematics in Collective Practices: A Framework for Analysis     

Geoffrey B. Saxe 《学习科学杂志》2013,22(2-3):275-300

This article presents a cultural-developmental framework for the analysis of children's mathematics in collective practices and illustrates the heuristic value of the framework through the analysis of videotaped episodes drawn from a middle-school classroom. The framework is presented in 2 related parts. The first targets the children's emerging mathematical goals in collective practices, with a particular focus on the complex role that artifacts play in children's emerging goals. The second part focuses on children's developing mathematics that takes form in their goal-directed activities: (a) Microgenetic analyses concern the process whereby children structure cultural forms like artifacts to serve particular functions as they accomplish emerging mathematical goals; (b) sociogenetic analyses concern the spread or travel of mathematical forms and associated functions within a community of individuals; and (c) ontogenetic analyses concern the interplay between the forms that children use and the functions that they serve over the course of children's development. The analyses of the classroom episodes points to the promise (and limitations) of the framework as a method for furthering our understanding of the interplay between social and developmental processes in children's mathematics.  相似文献   

Title I: The Evolving Research Base     

Geoffrey D. Borman 《Journal of Education for Students Placed at Risk》2013,18(1-2):27-45

For the past 35 years, Title I of the Elementary and Secondary Education Act has been the largest and most important federal resource for reforming high-poverty schools. Drawing on recent research, this article documents what we know about Title I's overall effectiveness and discusses how it may become a more effective intervention. The author concludes by making 3 policy recommendations for fostering better research and better programs: implement a rigorous and uniform national accountability system; support continued research and development of replicable programs and methods for improving schooling for disadvantaged children; and encourage large-scale randomized experiments of promising programs and practices.  相似文献   

Student and Teacher Outcomes of The Superkids Quasi-Experimental Study     

Geoffrey D. Borman  N. Maritza Dowling 《Journal of Education for Students Placed at Risk》2013,18(3):207-225

In this article, we report kindergarten student and teacher outcomes from a quasi-experimental evaluation of The Superkids, a systematic, phonics-based, comprehensive K-2 reading program. We recruited 23 kindergarten teachers to implement The Superkids program from a diverse, yet predominantly ethnic minority, group of classrooms from across the United States. We then employed a precise computerized matching methodology to derive a statistically equivalent comparison group of 20 control teachers who implemented their standard “business as usual” core literacy program. Multilevel analyses of classroom-level effects of The Superkids revealed achievement advantages of more than 1/10 of a standard deviation, d = 0.11, to 1/4 of a standard deviation, d = 0.25, for the treatment group on the 5 subtests from the Stanford Achievement Test, 10th edition (SAT-10). Four measures of teachers’ self-reported satisfaction with the core reading program used in their classrooms also revealed statistically significant advantages for Superkids of nearly three-quarters of a standard deviation, d = 0.72, to nearly 1½ standard deviation units, d = 1.49.  相似文献   

Potentiation of responding on a VR schedule by a stimulus correlated with reinforcement: Effects of diffuse and localized signals     

Phil Reed  Todd R. Schachtman  Geoffrey Hall 《Learning & behavior》1988,16(1):75-82

In Experiment 1, rats were trained to leverpress on a variable ratio (VR) 30 schedule with a 500-msec delay between the reinforced response and food delivery. Subjects that experienced a signal during the delay responded faster than did control subjects that received the stimulus un-correlated with reinforcement. Higher response rates were obtained when the stimulus used to signal reinforcement was auditory rather than visual. Experiments 2 and 3 compared the effects of signaling reinforcement with either a localized or a diffuse light on responding maintained by VR schedules of reinforcement. Elevated response rates were observed with the diffuse stimulus, but the localized stimulus failed to produce such potentiation. Experiment 3 also examined the conditioned reinforcing power of localized and diffuse visual stimuli. These results are discussed with reference to (1) theories of selective association and sign tracking and (2) their implications for current theories of signaling reinforcement.  相似文献   

Enacting silence: Residual categories as a challenge for ethics,information systems,and communication     

Susan Leigh Star  Geoffrey C. Bowker 《Ethics and Information Technology》2007,9(4):273-280

Residual categories are those which cannot be formally represented within a given classification system. We examine the forms that residuality takes within our information systems today, and explore some silences which form around those inhabiting particular residual categories. We argue that there is significant ethical and political work to be done in exploring residuality.  相似文献   

The Opportunities of Distance     

Geoffrey Bolton 《Distance Education》1986,7(1):5-22

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The Business of Educational Development     

Geoffrey Hubbard 《British journal of educational technology : journal of the Council for Educational Technology》1980,11(3):156-159

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Racial Attitudes among Caucasian Children: an empirical study of Allport's ‘total rejection’ hypothesis     

Geoffrey A. Short 《Educational studies》1981,7(3):197-204

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